Today marks six months since the explosion on the Deepwater Horizon, an event that caused oil to gush into the Gulf of Mexico for nearly three months. Half a year later, we neither have a definitive answer about what caused the disaster, nor, as Rep. Ed Markey (D-Mass.) points out, have we even heard from the company’s new CEO, Bob Dudley.

Dudley officially took over as CEO on October 1. Markey, chair of the Energy and Environment Subcommittee in the House Energy and Commerce Committee, has sent multiple requests for Dudley to appear before Congress over the past few months, to no avail so far. Tony Hayward, Dudley’s gaffe-prone predecessor, made a rather unproductive appearance before the committee in June. Dudley’s appointment is supposed to reassure the American public that things are changing at BP, but he’s so far found it impossible to make time to talk to Congress.

She also points out that Republican obstructionism has not helped matters.

It’s probably worth noting yet again that the National Oil Spill Commission—the bipartisan panel that the Obama administration created to investigate the spill and recommend how to move forward with offshore drilling—still lacks the ability to compel folks like Dudley to testify. The House passed legislation granting the power of subpoena to the commission nearly unanimously, but Senate Republicans have blocked the bill in the upper chamber. Thus, the panel (which has released some scathing draft reports to date) still remains largely toothless when it comes to forcing key players to testify and produce crucial documents.